Carbureter



unrTan sTaTas PATENT.. america.

EDWARD ALBERT ROCKWELL, OF NEW YORK, Y.

CARBURETER.

Specification of Letters Patent.

)Patented Nov. 23, 1920.

Application filed July 28, 1916. Serial No. 111,755.

To all fw hom t may concern:

Be it known lthat I, rEDwaRD A. Rooi;- wELL, a citizen of the UnitedStates, and a resident of the city, county, and State of A New York., have invented certain new' and useful Improvements in Carbureters; and l do hereby declare the following to be a j full, clear, and exactdescription of the in- 'atmospheric pressure.

vention, such as will enable others skilledv in the art to which it appertains to make and use the same.

This invention relates to carbureters for internal combustion engines and has for its object to provide a novel carbureter in' which the proportion of fuel and air in the combustible mixture will be automatically varied for different engine speeds to obtain the proper mixture for best operation at thev particular speed and load.

A further object of the invention is to provide a fuel feed for the novelcarbureter by means vof which Athe feed of fuel to the spray nozzlewill be maintained constant y under a constant head without being affected by the relative elevation of the supply tank and the carbureter. By my improved feed the gasolene will be'drawn from the l supply tank at the proper ratevto maintain the constant head,'v with the supply tank below the level of the novel carbureter and at In present automobile practice the supply tank is either so positioned on the par as to always be above the level of the carbureter,

or else auxiliary devices are used. for forc part of the carbureter itself.

A further object of the invention is to provide a carbureter havingfthe above fea-- tures, in which the structure vcontains.aj

minimum of working parts and is free from complication and necessity o f fine adjust- -V ment. j y

In the preferred embodiments/ of the inmg or drawing the fuel from the main sup-4 in and forming an. indivisible vention disclosed herein the level ofI the fuel inv the feed chamber may be varied by the adjustment of a single threaded part and the regulation of the carbureterboth for fixed adjustment and for running control of the motor is effected through the adjustment of a single part.

Further objects of my invention will appearvfrom the following specification, taken in connection with the accompanying drawings, wherein Figure 1 shows one embodiment of my mproved carbureter in vertical section;

Fig. 2 1s a vertical-sectional View on line 2 2 of Fig. 1;

Figs. 3 and 4 are detail views of different l portions of the carbureter; and F 1g. 5 is a vertical sectional View of a portion of the carbureter showing a modified form of fuel feed.

Referring now to tl1edraw vings,1 indie.

cates the main casting embodying, as shown,v

a mixing tube or chamber 2 water-ljacketed as indicated at 3, for connection with the water circulating system ofthe motor to raise the temperature in thel mixing chamber and assist in the vaporization of the fuel. j

The main casting is designed at its upper end to connect. directly with the vintake manifold kof the motor, and' form a downward vertical extension of the manifold intake, and lis provided at its lower end with a lateral, horizontal extension having near its 4end an opening for the admission of the air through the air-controlling valve. 5 whose specic construction will be later described.

The liquid fuel is, in the embodiment shown in Figs. 1 to 4, supplied tothe mixing tube through a spray nozzle 6, projecting upwardly from the lower wall of the horizontal extension of the mixing tube. As shown, the spray nozzle comprises a tube threaded in the wall of the casting with its upper end ground to provide a seat for the -valve 7 by means of which the quantity of fuel will V4be' regulated at the spray nozzle.'

ln the construction showm the fuel is delivered to the spray nozzle by a supply pipe 12 preferably connected to the spray nozzle through passageQ inthe casting into which the lower'end-f the spray nozzle projects; the end lof the spray nozzle preferably extending ntoa-,cavity formed in, e. g., the upper face of a'plug'lO, which may be erably several inches above the outlet of the closed by a plug 26, having a vent openingl spray nozzle. Also formed in the casting below the chamber 14 and separated from it by, for example, a web 15 is shown a second chamber 16, herein termed, for convenience, the filtration chamber, 'to which may be connected the supply pipe 17 from the fuel tank. 'The web 15 is lshown provided with a central tubular extension affording a valve-controlled passage between the chamber landv the upper constant-level7 chamber 14, and surrounding the extension is shown a strainer or filter 18'of gauze, or the like, which may be .clamped in place by means of a plug 19 which may close the bottom of the filtration chamber 16, the construction being such that the strainer may be conveniently removed and cleaned or renewed.

The valve between the two chambers may consist of a ball 2 0 lying in the bore of the projection and resting against a valve seat surrounding the upper face of the passage through the web. yThe ball may be held against the seat by, ag., a spring 21, whose upper end may project into a counterboredV cavity in the lower end of a nozzle 22 which may be threaded into theaveb 15, as shown, to provide an inlet for the fuel at the upper end of the nozzle through, c. g., the lateral bores 23.

Surrounding the upper end of the nozzlel 22 is shown a hollow plug 24 threaded into the upper wall of the', cor1stantlevel"1 chamber 14, the walls. of the plug being inwardly tapered at its lower end to provide -a -somewhat separate portion or compartment of said chamber surrounding the inlet,

23 and also to provide a lwer opening of a bore ordinarily about equal to.the external diameter of the nozzle. y The upper end of the hollow plug 24, which may be vertically adjusted by rotation, in order to vary the 4cheei `at the nozzle 6, is shown as 27 of very small diameter, and above the f plug 26 a perforated cap. 28 and gauze-dia phragm 28a may be provided to vent opening from clogging.

The outer surface of the nozzle 22 may be protect the J fluted as shown at 29 in enlarged detail in Fig. 4, for a distance somewhat above and below the lower end of the hollow `vplug 24 to provide a passage for' the fuel from the hollow plug to the chamber 14, and thence through the pipe 12 to the spray nozzle.

v The length of the flut-ed portion is shown as extended beyond the necessary distance for the passage of the fuel in order to permit a vertical adjustment of the hollow plug to vary the level of the fuel in the chamber 14. as will be later described.

The constant-level chamber 14V is shown connected with the mixing tube 2 by an upwardly inclined orifice 30 above the end of the hollow plug 24, so that the pressure on the liquid in the chamber 14 is reduced upon each suction stroke of the piston of the engine, maintaining in effect asubstantially constant sub-normal pressure in thev constarrt-level chamber 14.` The tension of the spring of the ball valve' isl intended to be so adjusted that it will maintain the passage from the supply chamber 16 to the chamber 14 closed against the gravity pressure of the fuel in case the supply-tank is at a higher elevation than the filtration chamber 116. A

very light pressure will suffice for this purpose, so that the suction in the fuel chamber will be ample to lift the valve and feed the fuel. l`he vent 27 is provided in order' i the plug is cut oif fromthe remainder of the constant-level chamber 14.

Assuming the level of the liquid to be as shown in the drawing the constant head in the chamber 14 will supply fuel to the spray nozzle G, where it will be atomized and drawn into the engine. lVhen the fuel level in the chamber 14 falls below the opening into the hollow plug 24, the pressure within the chamber of the hollow plug will be reduced, the cross-section of the vent 27 being too small in4 comparison with the total area of'the fuel passage 'formed by the fluted surface of the nozzle to materially affect the reduction in pressure. The "suction, will los thereby be effective at the feed openings 23 `of the nozzle 22 to open the ball valve and chamber 16 full'of fuel when the tank is lower than the chamber, for any flow to'ward the tank will immediately cause the valve to close even before the vent 27 has restablished the air pressure in the hollow plug to atmospheric. To prevent an excessive pressure reduction in the chamber 14 a spring loaded safety valve may be provided as conventionally indicated at 39. This valve, involving no features of novelty, may contain of the engine at a much more ra id rate than" the consumption of the fuel by so that the level of the fuel'in the con stant-level chamber 14 will quickly rise, to

cover the opening. from the plug into the lower part of the constantd'evel chamber 14. The interior of the hollow plug will then be no longer equallyr affected by the suction of the engine, the flow of fuel thereto will be checked and through the vent 27 the .pressure on that portion of the chamber that is within the plug will again become atmo spheric.

The effect of this operation is to maintain a level'of the fuel inthe constant-level chamber 14 at substantially the lower edge of the hollow plug and thereby maintain the spray nozzle under a fixed head'or feed pressure, regardless of the level of the supply tank, and whether the car is running up hill or down hill.

ln Fig. 5, omitting tion means, l have shown a modified form of suction feed wherein the level of the fuel is maintained by means of a float'feed'valve. As here shown the constant-level. or float chamber 50 is formed in a projection on the mixing tube located in a position corresponding to the fuel chamber of the preferred design. The exit pipe 12 leads from the float chamber near the bottom thereof to the mixing tube, which maybe of 'the' same design as in the preferred 'construction and vis therefore not shown in the drawings. ln the form shown, the inlet pipe 17 which must lead Adirectly or indirectly from the fuel tank communicates with the. float chamber through. a. central tubel 51,` which may. be threaded in the cap of the float/chamber,

the threads of the lower end of the tube the usual hollow metal construction. rlhe lower end of the tube 51 is ground to form a valve seat for coperation with the float.

valve 53 carried byy a bridge-piece 54 attached to the bottom 4of the float. ,lV'hen j the level of the fuel in the float chamber rises above the desiredl point, the buoyancy of the ioat will raise the valve against the- -valve seat'and cut o the fuel.

The level may bevaried by adjusting thev tube 51 up and down in its threaded bearing in the The cap ofthe oat chamber is shown andthe space above the level ofthe fuel in the'chamber is shown connected with the mixing tube -by a port 55, so that the sucthe engine,`

`"may be verysmall while the ini/ade of any desired diameter,

tion *of the engine jwill maintain a subatmospheric pressure in the float chamber to positively draw the fuel in the float chamber from the supply tank, even though the level of the tankbe bfelow that of the float chamber. As the bore of the feed tube 51 float may be the reduced Y, fpressure of the. float chamber will not be disclosure of\any iltral -being preferably machined off rto serve as for the float 52 'here shown as of' Vprovided with a suitable air-tight closure,

sufficient to open the valve against the buoy.- ancy of the float, but when Vthe valve is opened by the descent of the float with the lowering of the liquid level, the suction produced in the float chamberby its connection with the'intake of the engine will positively feed the fuel into the float chamber.

The mechanism for simultaneously reg ulating the fuel and air will now `be described.' The lateral extension ofthe main casting is shown as fully open, at its outer end, and telescopically mounted in the bore of the projection is a valvefsleeve 31 having at its inner end a cam 32 extending through In the form shown the air is admitted to l the mixing tube through a lateral. opening "34 in the tube wall and thence to the bore Vabout half the circumference of the sleeve and operatively' engaging the needle valve of thevalve sleeve through an opening 35 in the wall of the valve sleeve. The opening 35 is positioned in the sleeve in such relation to the camw and the opening 34 that it is adjusted across the opening 34 during the partial rotation of the valve sleeve which lis .effective in regulating thev needle :valve L7. The opening 34 is substantially rectangular, whereasw the opening 35 has one straight'wall and one inclined wall so positioned that'the rotative adjustment of the valve sleeve brings a' greater or less portion of the"` opening 35 into registration with thev 'opening 34.. to Vthereby vary the air supply? The valve sleeve may be rotated by meai/l of any `suitable mechanism, and l have shownforthe purpose a lever arm 38 fast' on the endclosure of the valve sleeve, suit! able'stops being. provided'to limit the eX'- tent of adjustment. The valve sleeve is also mounted for longitudinal'adjustment in the mixing tube extension, which adjustment may be effected through a cam'lever 'mounted on the mainl casting. and engaging the. rojecting flange at the end ofthe sleeve va ve', as more par iticularly shown -in Fig. 8,fand this endwisemovement of theyalve sleeve is also effec` Y tive to regulate the air supply. As one means, to this end, the straight wall of the opening 35 is shown positioned beyond 'the the endwise adjustment of the sleeve withtion shown in the drawings.

out disengaging the head of the needle valve.

By rotatively adjusting the valve sleeve the quantity of fuel delivered from'the spray nozzle will be varied with the variations in area of the air opening. When, however, the valve is longitudinally adjusted, by` means of the cam lever 36, the air opening only will be adjusted.

-The operation of the device is as follows: Let it be assumed that the carbureter is attached to an automobile proceeding on a level road under conditions to place a light load on the motor. A reasonable speed of the car will therefore be maintained with small fuel consumption, and it will be assumed that the engine is receiving a proper mixture with the feed valve adjusted to the posi- Let it be supposed that the car has reached a hill, which causes the motor to slow down. To increase the power of the motor'so that it may drive' the car upthe hill, the sleeve valve is rotated by means of the lever arm 38 throughconnection to the usual steering post control of the automobile, in a direction to the right, ork

clockwise, as shown in Fig. 2, to thereby in- Y crease the opening of the needle valve and simultaneously increase the area of the air inlet. The suction of the motor will now 'be effective to draw -in an increased amount of air on each stroke through the increased air opening, and through the adjustment of the needle valve a greater quantity of the fuel will be discharged so that the engine will receive a more powerful charge at each stroke,`and deliver greater power at the shaft.

the inclined edge of the air opening and the desired relation of the air and fuel feed may be maintained. In case, however, the mixture, correct for certain conditions, is found to be too rich or too lean under other existing conditions, the ratio of the air and fuel opening may be altered by adjusting the air valve longitudinally of the tube by means of the cam lever 36 to obtain the desired regulation. This lever may be connected to a suitable control on the dash ofthe automobile but not on the steering post for the running control, as an occasional adjustment for abnormal conditions \is all that is required.

With an ordinary' butterfly throttle in the mixing tube above the fuel inlet, as is com'- By giving the proper relative contour to mon practice in carbureter construction, the

amount of fuel discharged at the spray nozzle is affected by the velocity of the air in the spray tube as well as the suction, no positive means for regulating the fuel flow being provided. rlhese factors do not maintain a uniform mixture at different motor speeds, but anauxiliary air valve has heretofore been necessary to supply an extra Quantity of air to the tube beyond the fuel inlet to dilute the mixture ,which is too rich at high motor speeds, while at low motor speeds where the greater power is required, the mixture is liable to be too lean.

In my improved carbureter, the fuel feed is not dependent on such variable factors, but is positively controlled by the needle valve, the e cam being shaped to give a sufliciently rich mixture at low speeds and a sufficiently lean mixture at high speeds to require no dilution.

My vacuum fuel feed may obviouslyv be used without my improved control valvev construction and vice versa, but l prefer to use both devices on the same carbureter for the reason that their combined use provides a proper proportion and sufficient quantity of fuel. and air in the mixture in relation to the engine speed under all running conditions.

I claim:

l. In a carbureter a constant-level fuel chamber, a source of supply. therefor,

a fuel passage therefrom, means independent of said fuel passage, fory pioducing a sub-atmospheric pressure in said chamber to positively draw the fuel into said chamber from the source of' supply, and means formaintaining a fixed level of fuel in said chamber independent of the rapidity of consumption of the fuel by the motor.

2. ln a carbureter, a constant-level fuel chamber, a source of supply therefor, a fuel passage therefrom, an inlet from the source of supply terminating in a portion of said chamber, means, independent' of said fuel passage,vfor producing a sub-atmospheric pressure in the portion of the chamber surrounding said fuel inlet when the level 'of the Q fuel 4falls below a predetermined point, "to thereby positively draw the fuel into said chamber from said source of supply.

roo

3. In a carbureter, a constant-levelabove a predetermined l V n Il l lll lill, l ll 'l chamber so controlled vby the level of thefuel as to produce a sub-atmospheric pres-v sure in the first mentioned chamber when the level of the fuel falls below-the said passage.

5. In a carbure'ter, the combination ofa mixing tube to be connected to an intake on v the motor, a fuel chamber ladjacent said mix-A .ing tube, a port connecting said chamber to said mixing tube whereby thesuction on the motor produces a sub-atmospheric pressure on the fuel in the-fuel chamber to positivelydraw the fuel into the fuel chamber, and means, controlled by the level of the fuel in the chamber, for checking the flow of fuel to the chamber when the level rises above a predetermined point.

6. In a carbureter, the combination o f a mixing tube to be connected to an intake on the motor, a fuel chamber adj acentsaid mixing tube, a port connecting saidchamber to said mixing tube whereby the suction on the `motor produces a sub-atmospheric pressure on .the fuel in the fuel chamber to positively draw the additional fuel into the said chamber, means, controlled lby the level of the fuel in the chamber, for checking the'flow of fuel to the chamber when the 'level rises above a predetermined point, a spray nozzle terminating in the mixing tube at a point below the fuel chamber, and means for 40 varying the predetermined level of the fuel in the fuel chamber to thereby vary the pressure head on the spray nozzle.

7. In a carbureter, the combination of a adjacent said mixingtube, a port between the upper portion of a lower compartment of said constant-level fuel chamber and the mixing tube, whereby the suction of the-en` gine produces subatmospheric pressurevin the said lower compartment, r second or upper compartment of said fuel chamber,

a passage between the said second compart- 4ment and the said lower compartment, said .passage being at a level below that of the said port into the mixing tube, and a feed passage from the source of supply terminating in said upper compartment, whereby the vsaid sub-atmospheric pressure in the lower portion of said constant-level chamber is effective to draw fuel through/the mentioned passage whenever/the level .Y of the fuel falls below the level of the passage between the upper and lower compartments of the constant-level and the chamber.

`8. In a carburetenthe'combination of a 65 i mixing tube, a fuel chamber adjacent said mix-ing tube, a port between the upper por! tion of a lower compartment ofthe fuel chamber and the mixing tube whereby 4the suction of the enginek produces sub-atmospheric pressure inthe said compartment, a second compartment .in saidl fuel chamber, a passage between the second compartment and the lower compartment of the---said chamber, said passage being below the port into the mixing tube, a feed passage from the source of supply terminating in said second compartment, and an air opening into said second compartment whereby the y compartment is normally maintained at at# mospheric pressure except when the level of the fuel in the lower compartments of the chamber falls below that'of the passage between the respective compartments.

In testimony whereof I aiiix mv signaturet EDWARD ALBERT RocKwELL. 

